105,282 research outputs found
Lattice-Renormalization of the Polyakov Loop
No full textZantow F. Lattice-Renormalization of the Polyakov Loop. Bielefeld: Fakultät für Physik; 2003
Three Paradigms of Juridical Knowledge: to Anniversary of Professor A. V. Polyakov
No full textArticle is dedicated to the 60-year anniversary of the professor of the chair of theory and law history and state of St. Petersburg State University, doctor of juridical sciences Andrey Vasilyevich Polyakov. In the article are analyzed some basic ideas of the communicative theory of law, creator of which is A. V. Polyakov. In this case the communicative theory of law by A. V. Polyakov it is considered in context of the processes, which characterize the development of the juridical science, by which, as for any other sciences, is inherent the sequential change of the paradigms of knowledge. In the article are separated three such paradigms, namely pre-classical, classical and postclassical. The author assumes that ideas of A. V. Polyakov, who is the best-known representative of the post-classical theory of law in Russia, they stimulate the change of the paradigms of lawful knowledge and thus contribute to overcoming crisis phenomena in the juridical science
Testing a theoretical resistance law for overland flow under simulated rainfall with different types of vegetation
No full textIn this paper a recently theoretically deduced flow resistance equation, based on a power-velocity profile, was tested using data collected for overland flow under simulated rainfall carried out in plots with vegetation. The available data were obtained exploring a wide range of rainfall intensities (from 60 to 181 mm h−1) and slopes (from 3.6 to 39.6%), and with four different types of vegetation. The database, including measurements of flow velocity, water depth, cross sectional flow area, wetted perimeter and bed slope, was divided in four datasets (one for each vegetation type), which allowed the calibration of the relationship between the velocity profile parameter Γ, the slope steepness, the flow Froude number, and the rainfall Reynolds number. The effect of rainfall intensity and different types of vegetation on flow resistance was investigated. The results showed that the theoretically deduced flow resistance equation allowed an accurate estimate of the Darcy-Weisbach friction factor for overland flow under simulated rainfall and in presence of vegetation. The developed analysis also suggested that flow resistance increases with rainfall intensity for laminar overland flow. The available data demonstrated that a quasi-independence between slope and mean velocity occurred. Finally, a single flow resistance equation resulted applicable to all investigated vegetation types and this equation was affected by flow regime represented by flow Reynolds number
Improved implementation of the Alicki–Van Ryn nonclassicality test for a single particle using Si detectors
No full textRecently a test of nonclassicality for a single qubit was proposed [R. Alicki and N. Van Ryn, J. Phys. A: Math. Theor. 41, 062001 (2008)]. We present an optimized experimental realization of this test leading to a 46 standard deviation violation of classicality. This factor of 5 improvement over our previous result was achieved by moving from the infrared to the visible where we can take advantage of higher efficiency and lower noise photon detectors
Dual simulation of a Polyakov loop model at finite baryon density: correlations and screening masses
No full textComputations of screening masses in finite-temperature QCD at finite density
are plagued by the sign problem and have been performed so far with an
imaginary chemical potential. Here, we use a dual formulation of a
Polyakov-loop model which allows the determination of screening masses at real
baryon chemical potential. This is a second paper in a series devoted to a
detailed study of dual Polyakov-loop models at finite density. While the first
paper was mainly devoted to establishing the phase diagram of the model, here
we compute correlation functions of the Polyakov loops and the second-moment
correlation length at non-zero chemical potential. This enables us to evaluate
numerically the screening masses from correlations of the real and imaginary
parts of the Polyakov loops. We also compute these masses in the mean-field
approximation and compare with numerical results. In addition, we provide a
quantitative improvement of the general phase diagram presented in the first
paper
Geração radiativa de repulsão vetorial para quarks leves
No full textDissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Ciências Físicas e Matemáticas, Programa de Pós-Graduação em Física, Florianópolis, 2014Abstract: We apply a non-perturbative analytical method, known as the Optimized PerturbationTheory (OPT), to the Polyakov-Nambu-Jona-Lasinio (PNJL) model in order to investigate physical quantities associated with the QCD phase transitions. We consider the Taylor expansion of the pressure in powers of µ/T obtaining the second cumulant (c2) which is associated to the quark number susceptibility. We discuss how the OPT nite Nc radiative (quantum) corrections induce a contribution to the pressure which behaves as a vector repulsion even when such a channel is absent in the original classical potential. Our results are then compared with the ones furnished by lattice QCD simulations and by the large-Nc approximation showing that, physically, the OPT results resemble those furnished by the latter approximation when a repulsive vector channel is explicitly included in the classical potential. In this case, both approximations fail to correctly describe the Stefan-Boltzmann limit at high temperatures. We discuss how this problem can be circumvented by taking the couplings to be temperature dependent so as to simulate the phenomenon of asymptotic freedom. Since this is the first time the OPT is applied to the PNJL we also discuss many technicalities associated with the evaluation of two loop (exchange) diagrams.Neste trabalho o método analítico não perturbativo conhecido como Teoria de Perturbação Otimizada (OPT) é aplicada ao modelo de Polyakov-Nambu-Jona-Lasinio (PNJL) para que quantidades físicas, associadas com as transições de fase da QCD, possam ser calculadas. A expansão da pressão em potências de µ/T é considerada para obter o segundo cumulante (c2) que é uma quantidade relacionada com a susceptibilidade do número de quarks. Primeiramente discutimos como as correções radiativas de Nc finito geradas pela OPT produzem uma contribuição que se comporta como um termo vetorial repulsivo mesmo quando este tipo de canal está ausente no potencial clássico original. Em seguida, nossos resultados são comparados com aqueles fornecidos pelas simulações na rede e também pela aproximação de Nc grande(LN). Fisicamente, os resultados da OPT são similares aqueles fornecidos pela aproximação LN quando um canal vetorial repulsivo é explicitamente incluido no potencial clássico. Neste caso, nenhuma destas aproximações analíticas produz corretamente o limite de Stefan Boltzmann para altas temperaturas. Contudo, nossos resultados sugerem como estes problemas podem ser contornados tomando-se as constantes de acoplamento como sendo dependentes da temperatura, de maneira que o fenômeno da liberdade assimptótica possa ser simulado. Esta é a primeira vez que a OPT é aplicada ao modelo de PNJL e por isto vários aspectos técnicos relacionados com o cálculo de diagramas de dois laços são também aqui apresentados
Investigation and development of the intelligent voice assistant for the Internet of Things using machine learning
No full textArtificial intelligence technologies are beginning to be actively used in human life, this is facilitated by the appearance and wide dissemination of the Internet of Things (IoT). Autonomous devices are becoming smarter in their way to interact with both a human and themselves. New capacities lead to creation of various systems for integration of smart things into Social Networks of the Internet of Things. One of the relevant trends in artificial intelligence is the technology of recognizing the natural language of a human. New insights in this topic can lead to new means of natural human-machine interaction, in which the machine would learn how to understand human's language, adjusting and interacting in it. One of such tools is voice assistant, which can be integrated into many other intelligent systems. In this paper, the principles of the functioning of voice assistants are described, its main shortcomings and limitations are given. The method of creating a local voice assistant without using cloud services is described, which allows to significantly expand the applicability of such devices in the future
On T dependence of the static potential V(T, R) in a finite volume
No full textWe study the dependence on of the static potential defined from Wilson loops and from Polyakov loop correlators on a finite lattice. For this study we employ a simple model with confinement, and compare with MC results
Dual simulation of a Polyakov loop model at finite baryon density: Phase diagram and local observables
No full textMany Polyakov loop models can be written in a dual formulation which is free of sign problem even when a non-vanishing baryon chemical potential is introduced in the action. Here, results of numerical simulations of a dual representation of one such effective Polyakov loop model at finite baryon density are presented. We compute various local observables such as energy density, baryon density, quark condensate and describe in details the phase diagram of the model. The regions of the first order phase transition and the crossover, as well as the line of the second order phase transition, are established. We also compute several correlation functions of the Polyakov loops
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